Igniter systems for gas ranges



1956 A. H. BRODBECK ET AL IGNITER SYSTEMS FOR GAS RANGES 2 Sheets-Sheet1 Filed Aug. 29, 1951 1956 A. H. BRODBECK ET AL IGNITER SYSTEMS FOR GASRANGES 2 Sheets-Sheet 2 Filed Aug. 29, 1951 United States Patent (3IGNITER SYSTEMS FOR GAS RANGES Almer H. Brodbeck, Webster Groves, andBradley C. Douglas, Kirkwood, Mo., assiguors to Magic Chef, Inc., acorporation of New Jersey Application August 29, 1951, Serial No.244,142

13 Claims. (Cl. 158-122) This invention relates to igniter systems forgas ranges and with regard to certain more specific features to anelectrically controlled system of the class described.

Among the several objects or" the invention may be noted the provisionof a low cost, reliable and safe electric igniter system for gas rangesin which a simple initial operation prepares the range for duty; theprovision of apparatus in the class described which makes the rangecompletely safe at all times when it is off duty; the provision ofapparatus of this class in which a signal is given of anyinoperativeness existing whenthe range is on duty; and the provision ofapparatus of this class which if an electric power failure occurs may bemanually set to operate until the power is restored. Other objects willbe in part apparent and in part pointed out hereinafter.

Briefly, the invention consists in a plurality of igniters for aplurality of burners which, when the range is prepared for duty, are allsupplied with gas and electric current for operation; otherwise not.Thus (in both forms of the invention shown) when the range is off dutythe igniters can never leak gas as sometimes occurs when an igniterconstantly supplied with gas is blown out. In one form of the inventionthe preparation of the range for duty consists in simply turning on oneof the control valves which results in supplying gas to all igniters, apressure switch coming into operation to supply current to all of theirignition coils. In the other form of the invention, the preparatoryoperation consists in closing a master switch which supplies all ofcertain igniter coils with current and through an electrical valvesupplies gas to all the igniters. In both forms of the invention theigniter coils of the igniters are grounded through igniter switchesuntil ignition has occurred. While grounded the voltage is not appliedto a signal lamp; but as soon as ignition has occurred and all ignitersare ignited, the grounding switches are all opened and voltage isapplied to the signal lamp which then shows that the range is properlyprepared for operation of its burners. The signal lamp and the ignitercoils, being at this time in series, cause insufiicient voltage to beapplied to the coils for them to reach ignition temperature, thuspreserving them. For this purpose the signal lamp is designed to operateupon the voltage drop available to it with the ignition coils in seriestherewith.

The invention accordingly comprises the elements and combinations ofelements, features of construction, and arrangements of parts which willbe exemplified in the structures hereinafter described, and the scope ofwhich will be indicated in the following claims.

In the accompanying drawings, in which two of various possibleembodiments of the invention are illustrated,

Fig. 1 is an electromechanical diagram of one form of the invention;

Fig. 2 is a similar diagram of a second form of the invention;

Fig. 3 is a horizontal section of one of the control valves of thesecond form of the invention;

Fig. 4 is a vertical section taken on lines 4-4 of Figs. 2 and 3;

Fig. 5 is a cross section taken on lines 5-5 of Figs. 2 and 3, showingan on position of parts; and

Fig. 6 is a view similar to Fig. 5, showing an off position of parts.

Corresponding parts through out the drawings are indicated by the samereference characters.

Referring now more particularly to Fig. l, numerals 1 indicate burnershaving control valves 3, ignition ports 5 and ignition flash-back tubes7. The valves 3 are supplied from a main gas line 9 which is undercontrol of a solenoid-operated gas valve 11. The solenoid coil of valve11 is indicated at 13. When the coil is unexcited the valve normallycloses. It is provided with a manual trip 15 whereby, upon failure ofcurrent to the coil 13, the valve may be set to open position. Thearrangement is such that when the valve is manually set to open position(upon failure of current into coil 13), any resumption of flow ofcurrent cuts out the effect of the trip 15. Valves of this type areknown and further description is not necessary. An example of such avalve is one known in the trade as No. 1014-5, sold by McQuay- NorrisManufacturing Company of St. Louis, Missouri. Properties of these valvesare that they may be manually tripped to open positions during any offcurrent period but will resume the proper oif-and-on electricalresponses after excitation of coil 13.

At numeral 17 are indicated electrical igniters. These are located atthe ends of pilot lines 19 extending from the main gas line 9. Lines 19include adjustable throttles 20. The ends of the pilot lines 19 and theigniters 17 are adjacent the ends of the flash-back tubes 7.

Each ignlter 17 consists of an igniter coil 21, a grounding switch 23and a thermal link 25 which is exposed to heat from a flame 3 at the endof pipe 19 when the flame is ignited. Each link 25 is anchored at oneend to a frame 27 and is joined at the other end to a movable contact ofswitch 23. The stationary contact of each switch is insulated from theframe 27 as shown at 29. When a flame 43 has been ignited at the end ofa pipe 19 by its respective coil 21, the thermal element 25 is heated toopen the respective switch 23; otherwise, the thermal element closes theswitch.

Sufiicient information has been given in connection with the igniter 17for complete understanding of the present invention, but if furtherdetail of these are desired, they appear in the U. S. patent applicationof Bradley C. Douglas and Harry H. Pryor, Serial No. 246,284, filedSeptember 12, 1951, for Electric Pilot- Flame l'gniter and owned by theassignee of this application.

At 31 is shown a transformer on the range, the primary of which is fedfrom a voltage source 33 through a master control switch 35, also on therange. This switch 35 also controls a supply circuit 37 to the coil 13of the solenoid valve 11. The secondary of the transformer 31 supplies acircuit 39 in which are serially connected the igniter coils 21 and avoltage-operated pilot signal device such as a signal lamp 41. As Fig. 1shows, the switches 23 are all connected in parallel with the signallamp 41.

Operation is as follows:

Assume first that the master switch 35 is open. The circuits 37 and 39will then be dead, valve 11 closed, coils 21 and links 25 cold, switches23 closed and signal lamp 41 out. Since no gas is available throughvalve 11, no gas can flow either from the pilot tubes 19 or burners 1.The range is then off duty and completely safe and foolproof. Forexample, the owner may leave the premises without fear of any gasleakage from any blown-out pilot. Small children may tamper with thevalves 3 without undesirable results. Switch 35 is placed on the rangein a position accessible only to adults.

In order to place the range on duty, the master switch 35 is closed.Assuming that the line 33 is alive, circuits 37 and 39 will beenergized. The former excites coil 13 and opens valve 11, while thelatter excites all coils 21 in series, current flowing to ground throughany or all closed switches 23. At this time the pilot lamp 41 will beout because, in view of the closed switches 23, there is no voltageacross it. Gas now flows from the pipes 19 and is ignited by the glowingcoils 21. This heats the links 25 which expand to open switches 23. Assoon as all switches 23 are open, the lamp 41 has voltage applied to itin series with the coils 21. The voltage of circuit 39 is then made upof the sum of the voltage drops across the coils 21 and the lamp 41.Under these conditions, the coils carry current but the voltage drop oneach is insuflicient to cause them to glow, whereas the lamp is designedto light under its aliquot part of the voltage drop. The gas flowingfrom pipes 19 is thus ignited and flames 43 burn continuously.

In order to light any burner 1 its respective valve 3 is opened andsupplies it with gas. Some of it flows from ignition port 5, passes downto tube 43 and upon flash-back the respective burner is ignited. One ormore burners may be turned on and oil at will. When it is desired tothrow the range off duty, the switch 35 is opened, whereupon all burnersand pipes 19 are deprived of gas by the closing of valve 11. All of thepilot flames 43 are extinguished. The links 25 cool and the switches 23reclose.

If during on-duty operations any pilot flame 43 goes out, its respectivelink 25 will cool, reclosing its respective switch 23, thereby removingvoltage from the lamp 41 and applying full voltage to the coils 21 whichreheat so that the flame 43 that has gone out will relight. During thisinterval of relighting the signal lamp 41 goes out. If one or more ofthe igniters 17 should become deranged sulficiently that their flameswill not reignite, this condition is shown by the signal light 41 goingout. Thus the operator will know that the range is defective andrequires repairs. On other words, the range is not in proper conditionfor operation as to all burners and igniters unless the lamp 41 islighted.

Sometimes it will occur that a power line such as 33 will fail. In suchevent the valve 11 may be reopened manually by operating the trip 15.Then the operator can ignite all of the pilots with a match or the like,after which the valve 3 may be operated as usual. Whenever the powerline 33 is restored, the valve 11 becomes operative in response tocurrent and the trip returns to its valve-closed position, so thatthereafter the stove is under electrical control as long as the line 33is alive.

Another form of the invention is shown in Figs. 2-6. In this case theburners shown at 51 have control valves 53. The ignition ports are shownat 55 and the flashback ignition tubes at 57. The main gas line is shownat 59. The pilot igniters 17 are the same as those described inconnection with Fig. l and therefore carry the same reference charactersfor identical parts, no further description being required. Each isassociated with several ignition tubes 57. The pilot gas pipes 19,having adjustable throttle valves 20, are like those of Fig. l and areadapted to produce a flame 43. As before, a main electric circuit 33supplies a transformer 31, the secondary of which is connected in acontrol line 39. As before, the coils 21 are serially connected in theline 39 with a. voltage-operated pilot signal device such as a pilotlamp 41, their switches 23 being grounded and in parallel with the lamp41.

At 61 is shown a pilot manifold supplying pipes 19 and having aconnection 63 with each of the valves 53. It also has a by-passconnection 65 with the gas line 59, in which is a normally closed manualcontrol valve 67. The manifold 61 connects with a pressure switch 62,the pressure-transmitting diaphragm 69 of which controls a 4 switch 71inthe line 39. The switch 71 normally biases itself to open position andis closed upon the predetermined pressure in the manifold 61.

Details of the valves 53 are shown in Figs. 3-6. These include inlets 73from the gas line 59 and outlets 75 to the burners 51. They includeoutlets 77 to connections 63. Branch passages 79 supply gas from inlets73 for distribution to connections 77 and 63. The cores 81 of thesevalves carry ports 83 forming on-ofi connections between pipe 59 and theoutlets 75 to the burners. These cores also carry on-ofl' connections 85between branches 79 and connections 77, 63. The arrangement is such(Figs. 5 and 6) that when a control member 87 of a valve 55 is turnedcounterclockwise, gas will flow from the line 59 first to the pilotmanifold 61 and then to the respective burner 51 (see Fig. 5). Thisraises the pressure in the manifold 61 and closes switch 71 while gasflows also to the respective burner. Circuit 39 is energized, heatingcoils 21 which ignite the flames 43, switches 23 being initially closed.The flames heat the links 25 to open switches 23, whereupon the lamp 41lights and remains lighted as long as all pilot flames 43 are burning.Under these conditions, the voltage on coils 31 is reduced to a pointwhere they cease to glow.

It will be seen that the first valve 53 to be operated causes lightingof all of the pilot flames 43, i. e., the range is prepared for use oron duty, and then when any other valve 53 is operated, its burner willignite. If any pilot mechanism becomes defective or the pilot flame goesout while the range is on duty, the respective switch 23 will close,thus causing lamp 41 to be shunted out of the circuit and go out,signalling to the operator that something is wrong with the range,requiring a correction.

If the line 33 goes dead, then the operator may open by-pass valve 67 tosupply pressure to the manifold 61, sending gas to the lines 19whereupon the flame 43 may be ignited with a match for temporaryoperation until power is restored in line 33. When the latter occurs thevalve 67 is again closed.

When all valves 53 are turned 011, the pilot manifold bleeds oil? itspressure through throttles 20 and switch 71 opens, thereby openingcircuit 39. The range is then oil duty. The lamp 41 then goes out.

The primary difference between the Fig. 2 and Fig. l circuits is that inthe former the operation of any one valve 53 to open position (insteadof closing of switch 35 in Fig. l) prepares the range for operation atany burner by igniting all pilot flames 43. These flames remain burningas long as any one or more valves 53 is open. However, when all valves53 are turned off, as when a days cooking is over, all of the pilotflames go out. However, in both forms of the invention all pilot flamesgo out when the range is off duty.

It will be understood that while the preferred form of the invention isone in which the coils 21 of a group of igniters 17 are connected inseries, it would be possible to use a system wherein there is only oneburner and igniter, as for example, one in which only one of the burnersof Fig. 1 is used; or only the right-hand pair of burners in Fig. 2. Itfollows, of course, that such individual-igniter systems might bemultiplied on a single range. This would, in the case of Fig. 2, requirea plurality of pressure switches 63 and in both Figs. 1 and 2 a largertransformer. While such arrangement is not preferable, it partakes ofcertain advantages of the invention.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As many changes could be made in the above construction Withoutdeparting from. the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

We claim:

1. A gas range electric igniter system comprising means adapted tosupply gas under pressure, a main burner, a pilot burner located toignite the main burner, means adapted to connect the pilot burner withthe gas supply means, said pilot burner being adapted to produce a pilotflame, a pilot flame igniter coil, a normally closed thermal switchadapted in response to heat of the pilot flame to open, avoltage-operated pilot signal device, said signal device and thermalswitch being connected in parallel, and circuit means connecting saidigniter coil in series with the parallel-connected signal device andthermal switch.

2. Apparatus made according to claim 1 including an additional switch insaid circuit means adapted when open to deenergize the coil and thesignal device.

3. Apparatus made according to claim 2 including means biasing saidadditional switch to a normally open position, and means responsive topressure obtained from said gas supply means adapted for closing saidadditional switch.

4. Apparatus made according to claim 3, including a control valvearranged to effect coordinated flow of gas from the gas supply means tosaid pressure-operated switch and to one of the burners.

5. Apparatus made according to claim 4, wherein there is an additionalconnection between said gas supply means and said pressure-responsivemeans, said additional connection including a manually operative valve.

6. Apparatus made according to claim 1, wherein the gas supply meansincludes a normally closed solenoid valve, an operating coil for saidsolenoid valve which when energized opens the valve, a second circuitmeans connected to said operating coil of the solenoid valve, and amaster switch connecting a supply circuit with both of said circuitmeans to energize them when the switch is closed.

7. A gas range electric igniter system comprising a plurality ofburners, a gas supply line, a plurality of igniters, each igniterconsisting of a pilot gas line having outlet means adapted to produce apilot flame and connected with the supply line, an ignition coil, anormally closed thermal switch responsive to heating by said pilot flameto open, a voltage-operated pilot signal device a circuit connectingsaid thermal switches in parallel with the pilot signal device andconnecting said ignition coils in series with one another and in serieswith the parallel connected thermal switches and pilot signal device.

8. Apparatus made according to claim 7, including a solenoid valve inthe gas supply line, a coil in said valve adapted when energized to openit, a second circuit for said solenoid coil, and a master switch adaptedwhen closed to energize both of said circuits.

9. A gas range igniter system comprising a plurality of burners, a gassupply line, a pilot gas manifold, a plurality of igniters eachconsisting of a pilot connection with the pilot manifold, saidconnection including an outlet means adapted to produce a pilot flame,an igniter coil, and a normally closed switch adapted to open inresponse to heat from said pilot flame, a normally open pressure switchresponsive to pressure in said manifold to close, control valves eacharranged coordinately to control flow of gas from the supply line to themanifold and to a burner, a voltage-operated pilot signal device, and acircuit connecting in series said pressure switch, coils and the signaldevice, said igniter switches being connected in parallel with oneanother and with the signal device.

10. Apparatus made according to claim 9, wherein said supply line andsaid manifold have an interconnection independent of the connectionsbetween said valves and the manifold, said last-named connectionincluding a manual control means.

11. Apparatus made according to claim 10, wherein a transformer iscarried on the range for energizing said circuit and wherein said signallamp is carried on the range.

12. A gas range electric igniter system comprising a main gas supplyline, an electric supply line, a plurality of pilot flame igniters, eachigniter including a gas connection with said gas supply line and havingoutlet means adapted to produce a pilot flame, an igniter coil in eachigniter and a normally closed thermal switch in each igniter adapted toopen in response to heat of the pilot flame, a voltage-operated pilotsignal device, said signal device and thermal switches being connectedin parallel, a circuit connecting said igniter coils in series with oneanother and with the parallel-connected signal device and switches, anormally closed solenoid valve in the gas supply line having a solenoidcoil which when energized opens the valve, a second circuit connected tosaid solenoid coil, a transformer, and a master switch adapted whenclosed to connect the electric supply line with the transformer and withsaid solenoid coil.

13. A gas range electric igniter system comprising several burners, anigniter for each burner including an ignition coil and a gas outlet forproducing a pilot flame near the coil, means adapted to prepare eachburner for normal duty including an element adapted upon operation tosupply ignition current to the igniter coils and gas to said pilot flameoutlets, normally closed thermal switches, each responsive to the heatof one pilot flame to open, a voltage-operated pilot signal device, saidsignal device and thermal switches being connected in parallel, andcircuit means connecting said igniter coils in series with one anotherand in series with the parallel-connected signal device and thermalswitches.

References Cited in the file of this patent UNITED STATES PATENTS1,535,240 Morris Apr. 28, 1925 1,646,503 Steward Oct. 25, 1927 1,734,257Kraft NOV. 5, 1929 1,977,854 Knopp Oct. 23, 1934 2,381,591 Heymann Aug.7, 1945 2,398,215 Eskin Apr. 9, 1946 2,558,427 Fagan June 26, 1951

